Fan blades for use in many gas turbine engines comprise a hollowed blade body with a cover glued on to the blade body on the suction side of the blade. The cover closes the hollowed portion of the blade to complete the aerodynamic shape of the blade. This has the benefit of lowering the weight of the fan blade, minimizing the adverse impact of the hollowed portions on the aerodynamic profile of the blade if left uncovered, and lowers the cost of a fan blade compared with diffusion bonding. One of the risks inherent in the bonded cover design is the reliability of the adhesive used to attach the cover. If the capability of the adhesive in an engine environment over the time span at which the engine could be operated is degraded, or if there were loss of cover adhesion during a bird impact event, the cover loss could cause an imbalance for the fan hub to which the fan blade is attached. Improvements are therefore still needed in the art.